Index tabs for quick identification and selection of information from looseleaf or hardbound binders are a common feature of nearly every well-organized office. Typically, these tabs are provided as markings on certain sheets or pages of binders, books, notebooks, or other sheet material. In order to facilitate scanning and selection of pages, the index tabs are typically staggered or spaced, along two orthogonal planes. For example, the tab mounted on the side of a subsequent index sheet is positioned just far enough below the tab mounted on the side of the immediately preceding index sheet that the identifying text or characters or symbols appearing on both tabs can be seen when the binder is closed and viewed from the adjacent side. Uses for such index tabs range from simple referencing to presentations.
In general, indexing tabs are made in one of two ways. The tabs may be integrally formed as protrusions of the sheets themselves as shown, for example, in U.S. Pat. No. 4,184,699 issued to Lowe on Jan. 22, 1980. Alternatively, the tabs may comprise separate elements which are connected to the index sheets as shown, for example in U.S. Pat. No. 4,962,603 issued to Kao et al. on Oct. 16, 1990; U.S. Pat. No. 5,135,261 issued to Cusack et al. on Aug. 4, 1992; U.S. Pat. No. 5,340,427 issued to Cusack et al. on Aug. 23, 1994; and U.S. Pat. No. 5,389,414 issued to Popat on Feb. 14, 1995.
As Kao et al. indicates, forming index tabs as integral protrusions of the index sheet has been disadvantageous, since it has been difficult to machine print identifying text on the tabs. For example, it has been impractical to insert the entire index sheet into a typewriter in order to type text onto the protruding tab. It has also been difficult or impossible to feed index sheets directly through common office printers, such as laser or inkjet printers, without encountering jamming, feed size limit, or uneven printing problems.
It is desirable to print index sheets on laser or inkjet printers due to the great flexibility of what can be printed as well as the high print quality provided by such printers or the like. However, such printers require the sheet stock to be uniformly dimensioned, at least widthwise, according to standard sizes in order to be accommodated by the standard sized feeding tray or platform of such printers. Otherwise, the sheet stock will either tend to jam such printers or not even fit into such printers. Index sheets, having protruding tabs on the top or leading side first drawn into the printer, can also jam or stray from the correct feed path. Moreover, the sheet stock must be strong enough to withstand the stresses imposed on the sheets by the feeding mechanisms and pressure rollers, and must provide a uniformly smooth surface that will properly take up the toner. Because of these requirements, conventional index sheets having nonuniform widths due to protruding index tabs have been poorly suited for use in laser or inkjet printers.
This drawback is all the more pronounced when the tabs are to be used to mark the pages of a hardbound or softbound book. As a result, the identifying text is usually either handwritten onto the tabs, or else the text is printed on separate adhesive labels which are then placed on the corresponding tabs.
The present invention is directed to overcoming one or more of the problems as set forth above.